Department of Animal Nutrition, CCS Haryana Agricultural University, Hisar - 125004, (Haryana).
*Corresponding author: E-mail: aft@hau.ernet.in
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The effect of dietary crude fibre (5, 7, 9 and 11%) and enzyme supplementation on performance, feed intake, efficiency of feed utilization, excreta moisture, intestinal viscosity, relative intestinal weight, relative intestinal length, carcass yield and carcass composition of birds were studied. Three hundred and twenty day-old broiler chicks were randomly divided in eight treatments having two replicates in each treatment. The Isoproteinic (BIS, 1992) rations having 5 (T1), 7 (T2), 9 (T3) and 11 (T4) % crude fibre (CF) were formulated. The diets T5, T6, T7 and T8 were having multi enzyme mixture. Body weight gain at 6 week of age ranged from 1566.25g (5% CF unsupplemented) to 1825.33 (9% CF, enzyme supplemented). There was a significant (P<0.05) increase in body weight gain with increase in crude fibre levels in diets. Feed intake/bird for 6 weeks ranged from 3476.45 g (T1) to 4084.25 g (T4), indicating a significant (P<0.05) higher intake at increased crude fibre levels. During all the growth periods FCR was statistically similar among various treatments. Intestinal viscosity ranged from 1.22cS (T5) to 1.46cS (T4), which indicated a significant (P<0.05) increase in intestinal viscosity with increased crude fibre levels. There was a significant (P<0.05) reduction in digesta viscosity through enzyme supplementation. Excreta moisture ranged from 69.13% (T8) to 75.33 (T3) indicating a significant (P<0.05) increase at higher crude fibre levels and enzyme supplemented diets were having lesser moisture in excreta. The relative length of intestine (cm/100 g live weight) and relative weight of intestine (% of live weight) ranged from 10.46 (T6) to 12.56 (T3) and 3.94 (T5) to 5.51 (T3), respectively. The results indicated that relative length and weight of intestine was significantly (P<0.05) higher at higher crude fibre level than control and enzyme supplementation resulted in marked reduction in relative length and weight of intestine. Carcass yield, carcass composition and giblets yield did not show any definite trend. However, the relative weight of pancreas (% of live weight) ranged from 0.20 (T6) to 0.35 (T4), which increased significantly (P<0.05) with increase in crude fibre levels. The enzyme supplemented counterparts showed a significant (P<0.05) decrease in relative weight of pancreas. Mortality of birds ranged from 2.5 to 5.0% and post mortem revealed that death was not related to any dietary treatment.
Broiler, fibre levels, performance, FCR, carcass characteristics
